2 * Copyright (C) 2001 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
5 * This file is released under the LGPL.
8 #ifndef _LINUX_DEVICE_MAPPER_H
9 #define _LINUX_DEVICE_MAPPER_H
18 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
22 unsigned long long ll;
26 * In the constructor the target parameter will already have the
27 * table, type, begin and len fields filled in.
29 typedef int (*dm_ctr_fn) (struct dm_target *target,
30 unsigned int argc, char **argv);
33 * The destructor doesn't need to free the dm_target, just
34 * anything hidden ti->private.
36 typedef void (*dm_dtr_fn) (struct dm_target *ti);
39 * The map function must return:
41 * = 0: The target will handle the io by resubmitting it later
42 * > 0: simple remap complete
44 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
45 union map_info *map_context);
49 * < 0 : error (currently ignored)
50 * 0 : ended successfully
51 * 1 : for some reason the io has still not completed (eg,
52 * multipath target might want to requeue a failed io).
54 typedef int (*dm_endio_fn) (struct dm_target *ti,
55 struct bio *bio, int error,
56 union map_info *map_context);
58 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
59 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
60 typedef void (*dm_resume_fn) (struct dm_target *ti);
62 typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
63 char *result, unsigned int maxlen);
65 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
67 typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode,
68 struct file *filp, unsigned int cmd,
71 void dm_error(const char *message);
74 * Constructors should call these functions to ensure destination devices
75 * are opened/closed correctly.
76 * FIXME: too many arguments.
78 int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
79 sector_t len, int mode, struct dm_dev **result);
80 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
83 * Information about a target type
87 struct module *module;
93 dm_presuspend_fn presuspend;
94 dm_postsuspend_fn postsuspend;
97 dm_message_fn message;
101 struct io_restrictions {
102 unsigned int max_sectors;
103 unsigned short max_phys_segments;
104 unsigned short max_hw_segments;
105 unsigned short hardsect_size;
106 unsigned int max_segment_size;
107 unsigned long seg_boundary_mask;
108 unsigned char no_cluster; /* inverted so that 0 is default */
112 struct dm_table *table;
113 struct target_type *type;
119 /* FIXME: turn this into a mask, and merge with io_restrictions */
120 /* Always a power of 2 */
124 * These are automatically filled in by
125 * dm_table_get_device.
127 struct io_restrictions limits;
129 /* target specific data */
132 /* Used to provide an error string from the ctr */
136 int dm_register_target(struct target_type *t);
137 int dm_unregister_target(struct target_type *t);
140 /*-----------------------------------------------------------------
141 * Functions for creating and manipulating mapped devices.
142 * Drop the reference with dm_put when you finish with the object.
143 *---------------------------------------------------------------*/
146 * DM_ANY_MINOR chooses the next available minor number.
148 #define DM_ANY_MINOR (-1)
149 int dm_create(int minor, struct mapped_device **md);
152 * Reference counting for md.
154 struct mapped_device *dm_get_md(dev_t dev);
155 void dm_get(struct mapped_device *md);
156 void dm_put(struct mapped_device *md);
159 * An arbitrary pointer may be stored alongside a mapped device.
161 void dm_set_mdptr(struct mapped_device *md, void *ptr);
162 void *dm_get_mdptr(struct mapped_device *md);
165 * A device can still be used while suspended, but I/O is deferred.
167 int dm_suspend(struct mapped_device *md, int with_lockfs);
168 int dm_resume(struct mapped_device *md);
173 uint32_t dm_get_event_nr(struct mapped_device *md);
174 int dm_wait_event(struct mapped_device *md, int event_nr);
179 const char *dm_device_name(struct mapped_device *md);
180 struct gendisk *dm_disk(struct mapped_device *md);
181 int dm_suspended(struct mapped_device *md);
184 * Geometry functions.
186 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
187 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
190 /*-----------------------------------------------------------------
191 * Functions for manipulating device-mapper tables.
192 *---------------------------------------------------------------*/
195 * First create an empty table.
197 int dm_table_create(struct dm_table **result, int mode,
198 unsigned num_targets, struct mapped_device *md);
201 * Then call this once for each target.
203 int dm_table_add_target(struct dm_table *t, const char *type,
204 sector_t start, sector_t len, char *params);
207 * Finally call this to make the table ready for use.
209 int dm_table_complete(struct dm_table *t);
212 * Table reference counting.
214 struct dm_table *dm_get_table(struct mapped_device *md);
215 void dm_table_get(struct dm_table *t);
216 void dm_table_put(struct dm_table *t);
221 sector_t dm_table_get_size(struct dm_table *t);
222 unsigned int dm_table_get_num_targets(struct dm_table *t);
223 int dm_table_get_mode(struct dm_table *t);
224 struct mapped_device *dm_table_get_md(struct dm_table *t);
229 void dm_table_event(struct dm_table *t);
232 * The device must be suspended before calling this method.
234 int dm_swap_table(struct mapped_device *md, struct dm_table *t);
237 * Prepare a table for a device that will error all I/O.
238 * To make it active, call dm_suspend(), dm_swap_table() then dm_resume().
240 int dm_create_error_table(struct dm_table **result, struct mapped_device *md);
242 #endif /* __KERNEL__ */
243 #endif /* _LINUX_DEVICE_MAPPER_H */